Short-term outcomes of mild (≥30 ℃) vs . moderate hypothermic circulatory arrest in aortic arch surgery

Hypothermia and antegrade cerebral perfusion (ACP) strategies in open aortic arch surgery (AAS) have improved significantly. The significance of the gradual temperature rise to mild hypothermia is quite apparent, however, its safety remains a challenge. Therefore, our objective was to explore the safety and efficacy of mild hypothermic circulatory arrest (Mi-HCA, ≥30 ℃). This retrospective cohort study enrolled in a total of 372 patients, and was performed at the Beijing Anzhen Hospital between January 2017 and November 2022. Among the 372 patients, 81 received AAS at ≥30 ℃, and the remaining 291 received the same at 22-29.9 ℃. Most acute type A aortic dissection (ATAAD) patients received total arch replacement (TAR) and frozen elephant trunk (FET) operation. Mi-HCA patients exhibited strongly augmented systemic temperature (26.19±1.63 . 31.40±0.79 ℃, P